Researchers have found that contrails – the white lines that airplanes leave behind in the sky – are a major cause of global warming and their impact on the climate was expected to triple by 2050.

The study, published on Thursday in the journal Atmospheric Chemistry and Physics, found that due to increased air traffic activity, contrail-induced warming was expected to be thrice larger in 2050 than what it was in 2006.

Contrails change global cloudiness which creates an imbalance in the Earth’s radiation budget – called radiative forcing – that results in warming of the planet. The larger this radiative forcing, the more significant the climate impact.

Noting that non-carbon dioxide climate impacts could not be neglected, researchers said that the increase was predicted to be faster than the rise in carbon dioxide radiative forcing since expected fuel efficiency measures would reduce carbon dioxide emissions.

In 2005, air traffic made up about five per cent of all anthropogenic radiative forcing, with contrails being the largest contributor to aviation’s climate impact. Pixabay

The increase in contrail radiative forcing was due to air traffic growth and a shift of flight routes to higher altitudes. According to researchers, cleaner aircraft emissions would solve part of the problem. In 2005, air traffic made up about five per cent of all anthropogenic radiative forcing, with contrails being the largest contributor to aviation’s climate impact.

“It is important to recognise the significant impact of non-carbon dioxide emissions such as contrails on climate and to take those effects into consideration when setting up emission trading systems or schemes like the Corsia agreement,” said the study’s lead author Lisa Bock from the German Aerospace Center.

FILE - Then-U.N. Secretary-General Ban Ki-moon addresses a development conference in Zurich, Jan. 22, 2016. Behind him on a screen are displayed the 17 goals of the U.N. 2030 Agenda for Sustainable Development. VOA

Growing inequality and climate change will not only derail progress toward global sustainability goals but also will threaten human existence, leading scientists said Wednesday at the United Nations.

The world is falling off track on ambitious global development goals adopted by U.N. members, a panel of scientists said in an independent assessment report released at U.N. headquarters.

Member nations unanimously adopted 17 sustainable development goals known as SDGs in 2015, setting out a wide-ranging “to-do” list tackling conflict, hunger, land degradation, gender equality and climate change by 2030.

The bleak assessment report was released ahead of a sustainable-goals summit scheduled at the United Nations this month.

Growing inequality and climate change will not only derail progress toward global sustainability goals but also will threaten human existence, leading scientists said Wednesday. Pixabay

“Overall, the picture is a sobering one,” said Shantanu Mukherjee, policy chief at the U.N. Department of Economic and Social Affairs. “One element of this is increasing inequality. … Another is the pace at which nature is being degraded by human activity, whether it is climate change or biodiversity loss.”

The independent panel of scientists investigated the ways and systems in which humans and the environment are linked and interact, said Peter Messerli of the University of Bern,
Switzerland, the co-chair of the group of scientists.

“These systems are on a very worrying trajectory, threatening the very existence of humanity,” he told reporters. “We have not realized the urgency to act now.”

Countries must put into practice ways to address vast gaps in wealth distribution and access to economic opportunities and technological advances that undermine innovation and economic growth, the report said.

“Each country has to decide,” Jean-Paul Moatti, chief executive of the French Research Institute for Development and one of the scientists who compiled the report.

“This has to be corrected,” he told the Thomson Reuters Foundation.

The report called on nations to focus on food and energy production and distribution, consumption and urban growth to find ways of building sustainable development.

The world is falling off track on ambitious global development goals adopted by U.N. members, a panel of scientists said in an independent assessment report released at U.N. headquarters. Pixabay

The cost of implementing the global goals has been estimated at $3 trillion a year.

These are not the first grim predictions made for the fate of the goals. Earlier reports have said they were threatened by the persistence of violence, conflict and destabilizing climate
change.